An image generation device is applied to, for example, the head-up display device disclosed in PTL 1 and this image generation device includes a light source that emits a laser light beam, a scanning unit that generates an image by scanning the laser light beam from the light source, and a light adjustment unit that is disposed in the light path of the laser light beam between the light source and the scanning unit, includes a liquid crystal element for controlling the polarization angle of the laser light beam, and adjusts the light intensity of the laser light beam toward the scanning unit. The image generation device obtains the dynamic range of the brightness of an image by attenuating the light intensity of a laser light beam using the light adjustment unit.
In addition, in the liquid crystal element disclosed in PTL 1, the positive electrode and the negative electrode are applied alternately at intervals of the frame cycle as an applied voltage to the liquid crystal element to prevent burn-in.
By the way, in an image generation device to be applied to a head-up display or the like installed in a vehicle or the like, the ambient temperature is apt to change and the difference in the temperature is large. Since the output characteristic of a semiconductor laser light source emitting a laser light beam changes when the ambient environment temperature changes, even if the light source is driven similarly, a laser light beam having a desired light intensity cannot be output.
To address such a problem, the image generation device (laser scanning display device) disclosed in PTL 2 causes the light source to output a laser light beam having a desired light intensity by detecting the light intensity of the laser light beam using a light detection unit and continuously or intermittently correcting the driving of the light source based on the light intensity signal detected by the light detection unit.